1990 Free flow exhaust

Kevin Gouge · Post by **Kevin Gouge** » Sun Sep 23, 2001 11:21 am

This may be a dumb question.

If I install a free flow exhaust what happens to the wiring from the sensor in
the catalytic converter ?

Will the car need tuning or will the computer handle the change?

Any feed back would be helpful.

Kevin

carl.halvorsen · Post by **carl.halvorsen** » Sun Sep 23, 2001 7:54 pm

Your MX5 already has a free flow exhaust, it is standard on the MX5.

Carl

Fletcher Blades · Post by **Fletcher Blades** » Mon Sep 24, 2001 7:26 am

Whilst, as Carl suggests, the MX-5's standard exhaust is considerably free-er
flowing than many family sedans or shopping baskets, that does not mean that
(small) gains cannot be had by moving to larger piping and a less restrictive
muffler.

Generally, you will only be replacing the section behind (or after) the
catalytic converter, and no extra tuning is required. The ECU has a feed-back
loop incorporating an air-flow meter in the intake, and a Oxygen sensor in the
exhaust, which can handle the change in air/fuel requirements that minor
intake/exhaust modifications will cause.

The general consensus is that going larger than 2 1/4 inch piping for the
1600, or 2 1/2 inch for the 1800 will become detrimental.

Fletch.